spark plugs

Anonymous · October 8, 2004, 23:58

how easy is it to change?
and what set of plug would pl recommend?
thinking of going for the hks iranium tip or NKG platinum ones???

Anonymous · October 9, 2004, 00:30

The stock spark plugs are iridium, and the recommended replacement interval is 120,000 miles (190,000 km).

I don't know how easy they are to change, but at 8000 miles a year mine will probably outlast the car (but if I do still have the car in 12 more years I'll pay the dealer to change them).

Anonymous · October 9, 2004, 02:42

Speaking of sparkplugs, I have a 2001 with less than 9600 miles on it (I garage it with the first snow and don't light it up again until the salt is off the roads). My CEL came on and stayed on. My mechanic put it on the computer, which detected intermittent missing on two cylinders. He checked everything else out and concluded I needed to replace the plugs. When he removed them, they looked good except for a light carbon coating all over them. When replaced with OEM iridium plugs, the engine ran noticeably smoother and no longer stumbled on start-up. He suggested that (1)the plugs were being fouled by the rich start-up mixture and/or (2)I wasn't driving hard enough or fast enough. So, I have started upshifting at 3000rpm and downshifting at 2300rpm (in city driving), since I don't need to be replacing $16 dollar plugs every 10K miles. The engine is running noticeably smoother and I have only lost 0.5 mpg in gas mileage. (I had been satisfied to cruise at 2000rpm in 5th gear on the city thoroughfares; I continue to do 70 - 80 mph on the freeways). I use Shell 93 octane Premium, exclusively.

Anonymous · October 9, 2004, 07:18

When my 2 was in for a large service in july it had done 32000 miles
the bill come to arounf £225.00, I noticed on the parts list that there was a set of sparkplug and the service desk confirmed that they had fitted new plugs, But @ Around £6.50 for the set i thought it was a littel cheap for platinum plugs, I thought that if the car is fitted with platinum then you would think they would replace with the same, Anyway the car didnt fun as smoothly as it did before the service and it felt like it wonted to stall on tick over, so i whent down to trusty Halfords and bougt a set of Bosh
super multi spark plug which i but in, the once that i removed were new but were just aldenery plug, the Bosh plugs were fitted and that cured the rough running and the tickover was back to normal MPG whent up
i get around 37-39 MPG useing Optimax

aaronjb · October 9, 2004, 11:18

Quote from: "maxum"Bosh super multi spark plug

The ones with four earth electrodes? They're horrible, horrible plugs s:(

s:( I recall reading a test (done a few years ago, admittedly) that showed a car lose several bhp (i.e. more than 3bhp) with those fitted..

All the four earth electrodes seem to do is shield the spark from the mixture, which isn't really what you're after..

When it comes time to replace them, I'd stick a decent set of NGK platinum or Iridium plugs in there if I were you..

JMHO s:)

s:)

Tem · October 9, 2004, 13:21

Quote from: "FairportSpyder"The stock spark plugs are iridium, and the recommended replacement interval is 120,000 miles (190,000 km).

They are iridiums only in US. In Europe they are the normal copper ones and the recommended replacement interval is 60,000km (~40k miles).

(not sure about japanese imports...anyone?)

Anonymous · October 9, 2004, 13:43

So in Europe you get things like LSD and 6 spd, and over here we get spark plugs? I feel better now.

Tem · October 9, 2004, 13:44

Quote from: "FairportSpyder"So in Europe you get things like LSD and 6 spd, and over here we get spark plugs? I feel better now.

s:lol: :lol: s:lol:

heathstimpson · October 9, 2004, 19:58

Quote from: "maxum"normal MPG went up
i get around 37-39 MPG useing Optimax

s:shock: :shock: s:shock: s:shock: :shock: s:shock: s:shock: :shock: s:shock: That much

Anonymous · October 10, 2004, 01:02

as my 2 is j-spec i think i'll change the plugs as the car is idleling at 400-500 rev which makes the car seems like it about to stall....
the thing is, is it easy to change? i have change it in other cars but i haven't had time to look at the 2

Anonymous · October 10, 2004, 22:37

Quote from: "duongs"as my 2 is j-spec i think i'll change the plugs as the car is idleling at 400-500 rev which makes the car seems like it about to stall....
the thing is, is it easy to change? i have change it in other cars but i haven't had time to look at the 2

It shouldn't be too hard, I've had a quick look and it *seems* to be pretty straight forward s:roll: :roll: s:roll: s:wink: :wink: s:wink:

For anyone who hasn't changed spark plugs before here's roughly what's involved;

It looks like you start with the hardest bit - getting the plastic cover off the top of the engine! s:lol: :lol: s:lol: There's a couple of nuts holding it on towards the back (looking into the engine bay from the back of the car) of the engine and a couple of round plastic clips with "odd heads" at the front - the latter looking the trickiest to remove - although I seem to be able to turn mine just with my fingers - i.e. no special tool required.

Once this is off it should just be a case of removing the HT-leads (by the rubber boot of course - not the lead as some (grease) monkeys did when they serviced my Pops previous car s:shock: :shock: s:shock: ) then taking out the old plugs.

You need a special spark-plug socket to do this (IIRC a 16mm one s:?: :?: s:?: ) - they have a rubber bit in the end to hold the plug in and an extension bar of the right length so that the socket reaches the wrench. This may be tricky too - as there's not much space between the top of the engine and the rear brace / body work.

When putting new spark plugs back in I always start by putting the plug in the socket then "hand-screwing" them in, holding on to the extension bar - not using the wrench to start with. Spark plugs are fairly easy to cross thread, so doing it this way means that you should be able to feel if the plugs are going back in true.

Then torque 'em up and put the leads and cover back on. BTW, can anyone with a workshop manual tell me what the correct torque for the spark plugs is s:?: :?: s:?: This is one instance where "FT" is certainly going to be too tight! s:lol: :lol: s:lol:

Tem · October 11, 2004, 06:55

Quote from: "Mr 2"Then torque 'em up

And make note of this s8)

s8) It's too easy to overtighten them, if you don't use a torque wrench and after that you have nothing to torque them into anymore s:? :? s:?

Btw, some say you shouldn't use a torque wrench that clicks, cause it sometimes breaks the plugs. Anyone ever experienced this?

Anonymous · October 11, 2004, 11:28

toyota said to me not to change the plugs. UK cars are suppos to be iridiam ( s:oops: :oops: s:oops: ), unless you want some VERY high quality platinum plugs put in. The most you can hop for for your money is shorter plug life and <1bhp for your >£25 each plugs (the only ones worth getting).

GSB · October 11, 2004, 11:39

Quote from: "Mr 2"Once this is off it should just be a case of removing the HT-leads (by the rubber boot of course - not the lead as some (grease) monkeys did when they serviced my Pops previous car s:shock: :shock: s:shock: ) then taking out the old plugs.

There are no HT leads. Theres a seperate coil pack on top of each spark plug that generates the nessesary high voltage.

Anonymous · October 12, 2004, 00:03

Quote from: "GSB"There are no HT leads. Theres a seperate coil pack on top of each spark plug that generates the nessesary high voltage.

Wow - I'm impressed - I didn't know 1zzy was that sophisticated! s:wink: :wink: s:wink:

I presumed it would have a similar "wasted spark" (I think that's what it's called!) ignition system as on the 1.8 VVC engine that was in my last car - a Rover 200 - it had (presumably) one coil on the back of the engine somewhere and a HT lead from it (no distributor) to each of the spark plugs.

So is the method of removing the coil-pack bit the same effectively as removing a HT lead? - i.e. do they just pull off?

Reading Vibratingsky's post above yours tho, it looks like it's not worth changing the spark plugs after all - if they are iridium jobbies!

Anonymous · October 12, 2004, 09:28

Honestly, fitting new spark plugs is SOOOO simple. One bolt to undo the coil pack, pull, out with old, in with new. As said you need a socket that grips the plug as they are quite deep.

You may aswell pull them and see what they are before you buy some new ones, i stripped a UK engine that i have spare and i'm sure they weren't iridiums, my J spec were but i've changed to GTS ones now.

Anonymous · October 13, 2004, 17:07

I keep looking at the black plastic cover on top of the valve cover thats protecting the coil packs and plugs. The cover is held on by two nuts to the rear of the cover and two plastic *>,*** things at the front. How do you release them without breaking them? Any ideas please.

Anonymous · October 13, 2004, 18:07

Quote from: "1ZZ"I keep looking at the black plastic cover on top of the valve cover thats protecting the coil packs and plugs. The cover is held on by two nuts to the rear of the cover and two plastic *>,*** things at the front. How do you release them without breaking them? Any ideas please.

It looks like it needs a special tool s:? :? s:?

However, if you can grip them tight enough with your fingers they do turn, well mine do at least! s:D

s:D

Anonymous · October 17, 2004, 20:39

Where's the cheapest place to buy these plugs then?
I saw some at a pretty good price on ebay.com in USA but none of them would post to UK. Why not?

roger · October 17, 2004, 22:26

I was looking at my manual. Not sure what is actually on the car Denso or NGK plugs, but the following link is to NGK specs for MR2 from US site. The manual shows the V Power as being the original OEM

http://www.ngksparkplugs.com/apps/car_truck_suv/results.asp?engineid=36790

Anybody wanting irradium or whatever can pick from this.

Denso site not so revealling, but agrees wit the manual that K16R-U11 is the OEM

Anonymous · January 30, 2005, 02:34

The idea with modern ignition system design is to expose the incoming air/fuel mixture to as large an ignition source (spark) as possible. Opening spark plug gap will increase engine hp until a point of misfire is reached when the plug gap can no longer sustain an arc. Point type electrodes concentrate electrical charge and will reliably arc over wider gaps than conventional (flat tipped) electrodes. Platinum electrodes can be constructed in wire of fairly small diameter, and wide gaps can be reliably used. Iridium electrodes can be fabricated in even smaller diameters, making them the choice when reliable consistent ignition is required, especially in a lean burning engine.
My 2 pence worth from the US!